Combustion synthesis of calcium aluminates

Journal Article · Tue Oct 01 04:00:00 EDT 1996 · Materials Research Bulletin

DOI:https://doi.org/10.1016/0025-5408(96)00112-2· OSTI ID:415485

Fumo, D A; Segadaes, A M ^[1]; Morelli, M R ^[2]

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1. Univ. of Aveiro (Portugal). Dept. Ceramics and Glass Engineering
2. Federal Univ. Sao Carlos, Sao Paulo (Brazil). Dept. of Materials Engineering

Commercial calcium aluminate cements for refractory use are known to contain various phases, the hydration behavior of which is interdependent and not fully understood. Hydration studies normally require that pure oxides be synthesized. Solid-state synthesis of single aluminates requires high temperatures and full conversion is not guaranteed. Moreover, it is difficult to obtain a compositionally homogeneous product with this method. The present work discusses a straightforward combustion synthesis technique to prepare submicron calcium aluminates using the corresponding metal nitrates-urea mixtures, at low temperature and short reaction times. The effect of the ratio oxidizer/fuel in the redox mixture was investigated, namely, to find out if urea contents below stoichiometry were enough to trigger the explosive combustion of the fuel and the subsequent decomposition of the salts, and how that ratio affected the phase formation and the characteristics, e.g., morphology and grain size, of the powder produced.

• OSTI ID: 415485
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 10 Vol. 31; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
CALCIUM OXIDES
CHEMICAL REACTIONS
ELECTRON MICROSCOPY
GRAIN SIZE
MICROSTRUCTURE
MORPHOLOGY
NITRATES
POWDERS
REDOX PROCESS
STOICHIOMETRY
SYNTHESIS
UREA
X-RAY DIFFRACTION